Diagnosis Of Anterior Mediastinal Tumors Research Articles

Advantages of additional PET vs. MRI in the clinical diagnosis of anterior mediastinal tumors.

The present study retrospectively examined the diagnostic utility of adding positron emission tomography (PET) or magnetic resonance imaging (MRI) to computed tomography (CT) alone for preoperative diagnosis of anterior mediastinal tumors. A total of 104 consecutive patients who had undergone surgical resection of anterior mediastinal tumors were divided into two groups: Additional PET to another modality and no additional PET to another modality, and further subdivided into three groups: CT alone, additional MRI to CT and additional PET to CT. The sensitivity, specificity, and accuracy for diagnosing malignant tumors in each subgroup was calculated. Comparing the two groups, the diagnostic sensitivity was similar for additional PET (98.0%) and no additional PET (95.2%) groups; however, the specificity and accuracy for additional PET (75.0 and 92.2%, respectively) were significantly improved compared with no additional PET (31.6 and 65.0%, respectively). In the subgroup analysis, adding PET to CT showed an improvement in specificity and positive predictive value for detecting malignant tumors, compared with either additional MRI to CT or CT alone. Additional PET, but not MRI, has advantages over CT alone in clinically distinguishing benign from malignant tumors of the mediastinum.

Positron emission tomography/computed tomography as a clinical diagnostic tool for anterior mediastinal tumors.

The purpose of this study was to assess the usefulness of positron emission tomography/computed tomography (PET/CT) in the differential diagnosis of anterior mediastinal tumors. A total of 94 patients with anterior mediastinal masses or nodules (male, n = 41; female, n = 53; age, 17-84years) were retrospectively evaluated. All patients were evaluated by PET/CT and the masses or nodules were histologically diagnosed in our institution. Anterior mediastinal masses and nodules were classified into two disease categories: Low (thymic hyperplasia, thymoma, mature teratoma, and MALT lymphoma) and High (thymic carcinoid, thymic cancer, diffuse large B-cell lymphoma, T-cell lymphoblastic lymphoma, Hodgkin's lymphoma, and malignant germ cell tumors) groups. The sensitivity and specificity of maximum standardized uptake value (SUVmax) 7.5 for the detection of High group were 77% and 100%, respectively. The SUVmax distributions of the WHO histological thymoma types and Masaoka stage thymomas extensively overlapped. Masaoka stage III thymomas had significantly higher SUVmax than Masaoka stage I thymomas. Regarding the TNM classification, the SUVmax of T3 and T1b thymomas was higher than T1a thymoma. Although the SUVmax of each disease overlapped, PET/CT findings provided useful information for the differential diagnosis of anterior mediastinal masses.

A rare case report of thymolipoma in a 4-year-old child

Thymolipoma is a rare benign tumor of the anterior mediastinum with mean age of incidence of 20 to 30 years with rare occurrence in children. All clinicians are not aware of this entity and so the diagnosis is easily missed. It is defined as a mass forming lesion composed of circumscribed mature adipose tissue and unremarkable thymus. I present a case of 4-year-old child with history of breathlessness. USG chest of the child had revealed a space occupying mass in the anterior mediastinum of 5 x 6 x 4 cms. On resection, the 550 gm weight mass showed capsulated, soft to firm, yellowish-tan colored areas. Sections from the mass showed predominantly adipose tissue containing interconnecting cords of thymus. Although rare, thymolipoma must be considered in the differential diagnosis of anterior mediastinal tumors.

Four Cases of Invasive Anterior Mediastinal Tumors Definitively Diagnosed by the Chamberlain Procedure

Percutaneous needle biopsy, commonly used for a definitive diagnosis of anterior mediastinal tumors, is sometimes inconclusive because of the small size of the biopsy specimens and the histologic heterogeneity of the tumors. We herein report 4 cases of invasive anterior mediastinal tumors, in which the definitive diagnosis was made using the Chamberlain procedure. [Case 1] A 33-year-old man was found to have an anterior mediastinal tumor on chest X-ray and computed tomography (CT). The tumor was histologically diagnosed as thymic carcinoma (squamous cell carcinoma) using the Chamberlain procedure. After 3 courses of preoperative chemotherapy, the patient underwent surgery and postoperative radiotherapy. He remains well, 35 months after the biopsy. [Case 2] A 17-year-old boy was found to have a tumor in the anterior mediastinum on chest CT. His serum alpha-fetoprotein level was elevated to 2,461 ng/mL. Histological diagnosis of yolk sac tumor was confirmed using the Chamberlain procedure. He was treated with one course of chemotherapy, followed by surgery; he remains well 57 months after the biopsy. [Case 3] A 72-year-old man was found, on chest X-ray and CT, to have a left upper anterior mediastinal tumor with invasion of the subclavian vessels. The tumor was confirmed histologically as thymic (sarcomatoid) carcinoma using the Chamberlain procedure. Despite 2 courses of chemotherapy, the tumor continued to enlarge and metastasized to the lung and bone. The patient died 7 months after the biopsy. [Case 4] A 62-year-old woman under treatment for rheumatoid arthritis (RA) was found, on a chest X-ray, to have a right anterior mediastinal tumor. Histological diagnosis using the Chamberlain procedure suggested lymphoproliferative disorder, and the RA medication was discontinued. This was followed by a decrease in the tumor size and avoidance of invasive surgery. The patient remains well, 15 months after the biopsy. [Conclusion] The Chamberlain procedure proved useful for definitive diagnosis in all 4 cases of invasive anterior mediastinal tumors. We recommend the Chamberlain procedure for biopsy since it enables safe, rapid, and successful collection of tissue samples.

A Swollen Heart in Pregnancy

Thymic carcinoma is a rare malignancy of the anterior mediastinum. Its aggressive course and early metastases portend a poor prognosis. Presentation during pregnancy increases the risk of recurrence, metastases, and maternal death. We describe a case of a healthy, pregnant female with a history of thymoma presenting with cardiopulmonary distress from recurrent pleural and pericardial effusions. The patient responded to serial thoracenteses and pericardiocenteses but extensive work-up remained nondiagnostic. CT thorax revealed an enlarging thymoma with bulky lymphadenopathies. Subsequent pathology re-analysis of the original thymoma biopsy showed pan-cytokeratin, P63, and EBV-positive epithelial tumor cells, similar to our axillary lymph no de hematopathology and confirmed the thymoma as the primary malignancy. Clinicopathologic diagnosis of metastatic thymic carcinoma was finalized through multidisciplinary consensus. The patient responded well to radiation therapy but the mother and fetus died abruptly two weeks later. This case illustrates the diagnostic and therapeutic dilemmas of thymic carcinoma and its devastating consequences during pregnancy. The limited therapies in pregnancy and the sparse evidenced-based-medicine practices all contribute to poor outcomes. Attention to the differential diagnosis of anterior mediastinal tumors in pregnancy, evaluation of patients’ immunocompetency and EBV-status, re-analysis of prior tissue pathology, and early multidisciplinary clinicopathologic diagnosis are all encouraged to expedite therapy and reduce mortality. doi:10.4021/jmc375w

A Swollen Heart in Pregnancy

Thymic carcinoma is a rare malignancy of the anterior mediastinum. Its aggressive course and early metastases portend a poor prognosis. Presentation during pregnancy increases the risk of recurrence, metastases, and maternal death. We describe a case of a healthy, pregnant female with a history of thymoma presenting with cardiopulmonary distress from recurrent pleural and pericardial effusions. The patient responded to serial thoracenteses and pericardiocenteses but extensive work-up remained nondiagnostic. CT thorax revealed an enlarging thymoma with bulky lymphadenopathies. Subsequent pathology re-analysis of the original thymoma biopsy showed pan-cytokeratin, P63, and EBV-positive epithelial tumor cells, similar to our axillary lymph node hematopathology and confirmed the thymoma as the primary malignancy. Clinicopathologic diagnosis of metastatic thymic carcinoma was finalized through multidisciplinary consensus. The patient responded well to radiation therapy but the mother and fetus died abruptly two weeks later. This case illustrates the diagnostic and therapeutic dilemmas of thymic carcinoma and its devastating consequences during pregnancy. The limited therapies in pregnancy and the sparse evidenced-based-medicine practices all contribute to poor outcomes. Attention to the differential diagnosis of anterior mediastinal tumors in pregnancy, evaluation of patients’ immunocompetency and EBV-status, re-analysis of prior tissue pathology, and early multidisciplinary clinicopathologic diagnosis are all encouraged to expedite therapy and reduce mortality. J Med Cases. 2011;2(6):231-235 doi: https://doi.org/10.4021/jmc375w

Anterior mediastinal tumors: Diagnostic accuracy of CT and MRI

Purpose To compare the diagnostic accuracy for anterior mediastinal tumors among CT, MRI, and both CT and MRI, and to determine the optimal CT and MRI procedures for the diagnosis of anterior mediastinal tumors. Materials and methods Both CT and MRI were performed in 127 patients with pathologically diagnosed anterior mediastinal tumors. The patients included 48 cases of thymoma, 12 cases of thymic carcinoma, 12 cases of thymic cyst, 20 cases of mature teratoma, 13 cases of malignant germ cell tumor, and 22 cases of malignant lymphoma. The CT and MRI scans were assessed by two chest radiologists without knowledge of their clinical and pathologic data. The observers recorded various CT and MRI findings and their first choice of diagnosis. Results The two observers made a correct first-choice diagnosis in an average of 78 (61%) of 127 cases on CT, 71 (56%) of 127 cases on MRI, and 85.5 (67%) of 127 cases on both CT and MRI. These included 83% cases of thymoma on CT, 84% on MRI, and 85% on both CT and MRI; 38% cases of thymic carcinoma on CT and 13% on MRI, and 33% on both CT and MRI; 46% cases of thymic cyst on CT and 71% on MRI, and 63% on both CT and MRI; 58% cases of mature teratoma and 38% on MRI, and 78% on both CT and MRI; 35% cases of malignant germ cell tumor on CT and 27% on MRI, and 31% on both CT and MRI; and 55% cases of malignant lymphoma on CT and 43% on MRI, and 61% on both CT and MRI. There were significant differences between the diagnostic accuracy by CT and MRI in the cases with both thymic cysts and thymic carcinoma ( p < 0.05). Conclusion CT is equal or superior to MRI in the diagnosis of anterior mediastinal tumors except for thymic cyst. CT should be considered the modality of choice following chest radiography, however, in certain circumstances, such as thymic cyst with hemorrhage or inflammation which mimic solid tumor despite low enhancement, MRI may be better in distinguishing anterior mediastinal tumors. For more helpful information in the diagnosis of mature teratoma after CT, MRI may follow.

Primary Parathyroid Tumors of the Mediastinum

We describe 17 cases (9 women, 8 men; aged 36 to 72 years) of primary parathyroid tumors occurring primarily in the anterior mediastinum. Clinically and radiologically, all patients had an anterior mediastinal tumor. All patients had metabolic disturbances with calcium and phosphorus. Of 17 patients, 13 had clinical primary hyperparathyroidism, 1 had secondary hyperparathyroidism due to polycystic kidney disease, and 1 had a history of prostatic carcinoma and 1 of chronic obstructive pulmonary disease. In 1 patient, the tumor was found at autopsy. Grossly, the tumors varied in size from 2 to 7 cm in greatest dimension. Histologically, 2 tumors showed features of parathyroid carcinoma, and 15 tumors showed more conventional features of parathyroid adenomas. Six tumors were predominantly oncocytic, 6 were composed predominantly of chief cells, and 3 had mixed cellular composition. Immunohistochemical studies for chromogranin, synaptophysin, low-molecular-weight keratin (CAM 5.2), and parathyroid hormone were performed in 10 cases (8 parathyroid adenomas and 2 parathyroid carcinomas). All the tumors examined showed variable positive reaction for those antibodies. The cases highlight the importance of keeping primary parathyroid tumors in the differential diagnosis of anterior mediastinal tumors.

Primary Parathyroid Tumors of the Mediastinum

We describe 17 cases (9 women, 8 men; aged 36 to 72 years) of primary parathyroid tumors occurring primarily in the anterior mediastinum. Clinically and radiologically, all patients had an anterior mediastinal tumor. All patients had metabolic disturbances with calcium and phosphorus. Of 17 patients, 13 had clinical primary hyperparathyroidism, 1 had secondary hyperparathyroidism due to polycystic kidney disease, and 1 had a history of prostatic carcinoma and 1 of chronic obstructive pulmonary disease. In 1 patient, the tumor was found at autopsy. Grossly, the tumors varied in size from 2 to 7 cm in greatest dimension. Histologically, 2 tumors showed features of parathyroid carcinoma, and 15 tumors showed more conventional features of parathyroid adenomas. Six tumors were predominantly oncocytic, 6 were composed predominantly of chief cells, and 3 had mixed cellular composition. Immunohistochemical studies for chromogranin, synaptophysin, low-molecular-weight keratin (CAM 5.2), and parathyroid hormone were performed in 10 cases (8 parathyroid adenomas and 2 parathyroid carcinomas). All the tumors examined showed variable positive reaction for those antibodies. The cases highlight the importance of keeping primary parathyroid tumors in the differential diagnosis of anterior mediastinal tumors.

Nodular sclerosing Hodgkin's disease of the thymus gland

An asymptomatic anterior mediastinal mass in a 22-year-old man proved to be nodular sclerosing Hodgkin's disease of the thymus gland. Complete excision was possible via a left posterolateral thoracotomy. Postoperative chemotherapy was given. Follow-up after 1 year showed no residual disease. Nodular sclerosing Hodgkin's disease is an uncommon tumor of the thymus gland and should be incorporated in the differential diagnosis of anterior mediastinal tumors. Multimodality treatment is advocated.

Endodermal sinus (yolk sac) tumors of the anterior mediastinum.

Seven cases of endodermal sinus tumor (yolk sac tumor) primary in the anterior mediastinum are added to the literature bringing to 21 the number of reported cases. This germ cell tumor should be included in the differential diagnosis of anterior mediastinal tumors. It has occurred in males 13--49 years old who are often systemically ill. Since this tumor almost always produces elevated levels of serum alpha-fetoprotein, a strong presumptive diagnosis is possible prior to biopsy. The prognosis is poor. The two disease-free survivors of the 21 reported cases were both treated with a combination of excision and chemotherapy.